Washington — The US Supreme Court’s decision on Tuesday to examine the race-based admissions plan at the University of Texas raises the possibility it may rule in a way that dramatically reduces the use of affirmative action plans at public colleges and universities across the country.

At issue in the Texas case is whether that’s school’s use of affirmative action to supplement minority enrollment at the state’s flagship university violates the equal protection rights of nonminority students competing for the same places in the freshman class.

University officials relied on a Supreme Court decision in a 2003 case, Grutter v. Bollinger, to support its use of race in an attempt to achieve a critical mass of racial and ethnic diversity in every class taught at UT.

Critics say the effort is an abuse of the diversity rationale approved by the Supreme Court in 2003. Supporters say it is necessary to fulfill the university’s educational mission of providing a diverse learning environment.

Legal analysts said the court may use the Texas case to revisit – and perhaps overturn – the 2003 decision in which the majority justices established for the first time that classroom diversity could provide a compelling interest justifying the use of race-based affirmative action.

That decision in Grutter v. Bollinger involved an admissions program at the University of Michigan Law School. The justices voted 5 to 4 to uphold the race-based program.

The critical swing vote was cast by then-Justice Sandra Day O’Connor, who wrote in her decision that such race-based programs should be phased out as unnecessary within 25 years.

Since then, Justice O’Connor has been replaced on the high court by Justice Samuel Alito, who is far less open to race-based admissions plans than was O’Connor.

In addition to this rightward shift at the court, Justice Elena Kagan, an affirmative action supporter, is recusing herself from consideration of the case. Justice Kagan worked on the Texas case as the Obama administration’s solicitor general before joining the high court.

“The last time the court considered affirmative action in higher education was the 2003” Grutter case, says Brian Fitzpatrick, a professor at Vanderbilt Law School. “It is possible the court could use this case to overturn Grutter’s permitting universities to use affirmative action for diversity purposes.”

But he notes that it is not the only potential outcome. “It is also possible the court will narrowly focus on the unique circumstances of the University of Texas,” he says.

For example, if the court was troubled by the university’s broad use of race to attempt to achieve diversity in every classroom at the university, the justices could strike down that portion of the university’s plan as being outside the guidance offered by the high court in the 2003 Grutter decision.

More problematic from the perspective of affirmative action supporters is the possibility that the justices use the Texas case to completely reexamine the diversity rationale that was narrowly approved in 2003.

“The court is right to take the case, because the justices must keep an eye on what schools are doing,” says Roger Clegg, president of the Center for Equal Opportunity and a long-time critic of race-based admissions programs.

“Instead of preferences being phased out, in some ways they are getting worse – as our studies have documented,” Mr. Clegg said. “What’s more, as our nation becomes more and more multiracial and multiethnic, it becomes more and more untenable for our public institutions to label, sort, and discriminate on the basis of skin color and national origin.”

Ted Shaw, a Columbia Law School professor and former president of the NAACP Legal Defense Fund, says the decision to take the Texas case is “potentially troubling news for colleges and universities and those who support efforts to diversify institutions of higher education.”

At the University of Texas the vast majority of minority freshman enter by means of a state law that requires race-neutral admission for anyone in the top 10 percent of a Texas high school class. The university adopted a race-based supplement plan after the high court’s ruling in 2003.

It is that supplement plan that is at the center of the legal fight over the use of race in Texas admissions.

Shaw identifies four potential routes the Supreme Court might follow in the Texas case. “The court could uphold the University of Texas plan, it could strike it down as unnecessary in light of its race-neutral ‘Ten Percent’ plan without overturning Grutter, or it could abandon res judicata principles and revisit its 2003 decision in Grutter,” he says.

In addition, Shaw said the justices could dismiss the case as mootgiven that the plaintiff is about to graduate from the other university she applied to after being rejected by Texas.

An evenly divided court would affirm the lower court’s ruling upholding the Texas race-based plan. But if the same five justices that voted against a race-based plan in 2007 join forces in the Texas case, the plan may be in trouble.

“The court grant is not entirely a surprise,” Shaw said. “Affirmative action and diversity opponents have been looking for the ‘right case’ to overturn Grutter since the day it was decided.”

Joshua Thompson, an attorney with the conservative Pacific Legal Foundation, said the court’s decision to take up the Texas case was “good news for everyone who believes in equal rights and equal opportunities.”

“It is time for the court to take another look at this area of law, and stake out a clear position against race-based preferences and discrimination in university admissions,” Mr. Thompson said.

“Racial diversity in a student body does not guarantee a diversity of experience and perspectives,” he said. “A policy of race-based preferences and discrimination in admissions is not just unfair, it is unconstitutional under the equal protection clause of the 14th Amendment.”